SGM3207 Unregulated 60mA Charge Pump Voltage Inverter

GENERAL DESCRIPTION

The SGM3207 generates an unregulated negative output voltage from an input voltage ranging from 1.4V to 5.5V. The device is typically supplied by a pre-regulated supply rail of 5V or 3.3V. Due to its wide input voltage range, two or three NiCd, NiMH, or alkaline battery cells, as well as one Li-ion cell can also power them.

Only three external capacitors are required to build a complete DC/DC charge pump inverter. Assembled in a small package, the complete converter can be built on a 50mm2 board area. Additional board area and component count reduction is achieved by replacing the Schottky diode that is typically needed for start-up into load by integrated circuitry.

The SGM3207 can deliver a maximum output current of 60mA with a typical conversion efficiency of greater than 85% over a wide output current range. The fixed switching frequency is 19kHz.

The SGM3207 is available in SOT-23-5 package. It operates over an ambient temperature range of -40℃to +85℃.